The synchronization of a plurality of pieces of equipment possibly operating with clocks presenting different drifts in time and forming part of an assembly is a problem when it is necessary to drive these pieces of equipment simultaneously.
The synchronization of a plurality of inverters is a problem encountered when it is desired to simultaneously drive a plurality of inverters operating in parallel in order to supply a given load, a given rotating electric machine for example, with power.
In most cases, as is illustrated in FIG. 1, the synchronization of the pieces of equipment E1, . . . EN is achieved using a dedicated communication bus 1, via a clock signal, with the presence of one piece of equipment 2 playing the role of master for the clock. In case of loss of communication with the master piece of equipment or in case of failure of the latter, the synchronization is lost. In the case of application to delivery of power in a system in which the pieces of equipment are linked by power cables, this may lead to a loss of energy (reverse current) that will no longer be fed to the machine to be driven but to the other inverters. This circulation of energy may then lead to damage to the system.
To avoid these problems, it is known to use dedicated wired connections for the synchronization of the pieces of equipment. A “pure” clock is used to clock the pieces of equipment at the same speed.
Another solution consists in using one or more pieces of master equipment possessing a dedicated clock or a dedicated communication bus. In the case of a dedicated communication bus, the number of connections and cables is increased. This generates bulk in systems in which the space provided for the pieces of equipment is increasingly small.
Another drawback results from the fact that one or more pieces of equipment may be entirely dedicated to one function and that they cannot then play the role of master.
In the rest of the description, the expression “master piece of equipment” corresponds to a piece of equipment that is configured to manage the synchronization status of the other pieces of equipment.